As a racecar driver speeds down a racetrack, he is constantly having to make turns in order to stay in the race and avoid colliding with the wall. A car moving around a racetrack is a common example of centripetal acceleration — an integral part of circular motion.

Centripetal acceleration by a car can have various effects on people and objects. Let's say a racecar driver is about to participate in a race, but his victory clothes were just washed and are still wet! Thinking quickly, he decides to dump the clothes in the trunk of his car. When the 200 lap race begins, the driver takes off and keeps getting faster. Soon, he is well ahead of the other drivers because of his sheer speed, still making dangerous turns and managing to stay in the race. However, he is forced to make pit stops often to change his tires. Finally, the driver wins the race. From his trunk, he pulls out his now dry victory clothes and makes his way to prepare for the awards ceremony.

Creative Applications

1. Why is it that centripetal acceleration is always present in circular motion even when speed is constant?

2. How is centripetal acceleration likely to be "felt" by the driver when he performs fast turns?

3. Why do tires often have to be changed in a race? (Think: How does circular motion affect the tires?)

4. How are the clothes dried by the end of the race? (Hint: Think about how clothes are usually dried in a machine.)

5. In what ways might we increase the centripetal acceleration of the racecar-racetrack system?